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Publication numberUS4621668 A
Publication typeGrant
Application numberUS 06/758,167
Publication dateNov 11, 1986
Filing dateJul 22, 1985
Priority dateFeb 21, 1984
Fee statusLapsed
Publication number06758167, 758167, US 4621668 A, US 4621668A, US-A-4621668, US4621668 A, US4621668A
InventorsNorman N. York
Original AssigneeYork Norman N
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus for removing tree stumps and splitting logs
US 4621668 A
Abstract
A tractor supported and driven mechanism for removing tree stumps and splitting logs which causes linear movement of a rotary cutter disk for milling away stumps from the side portions thereof and a ram assembly forcing a log against a wedge member. The mechanism incorporates a frame structure having a hydraulically driven slide supported and guided by parallel structural members of the frame. The cutter disk is rotatably supported on the slide structure and is driven by the power take-off of the tractor by means of an elongated non-circular drive shaft which is received in driving engagement by a central non-circular drive opening of the cutter. The cutter disk is movable along the length of the non-circular drive shaft while maintaining driving engagement therewith.
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Claims(11)
What is claimed is:
1. Tractor supported and operated stump removal and log splitter apparatus, comprising:
(a) a frame structure adapted to be supported, raised and lowered by a hitch structure of the tractor;
(b) slide means being positioned for guided reciprocal movement on said frame structure;
(c) means for imparting linear reciprocal movement to said slide means;
(d) a non-circular drive shaft being mounted for rotary movement on said frame structure and adapted to be driven by the power take-off of the tractor;
(e) a rotary cutter element being rotatably mounted on said slide means and movable along with said slide means, said rotary cutter element having means providing sliding, non-rotatable relation with said drive shaft, whereby said cutter element is rotated by said drive shaft and is capable of simultaneous linear movement; and
(f) log splitting means mounted on said frame structure for splitting a log positioned thereon.
2. The apparatus of claim 1 wherein said log splitting means includes a horizontally disposed log support member supported above a rear extension of said frame structure.
3. The apparatus of claim 2, including:
(a) ram means being positioned for guided reciprocal movement relative to said support member and adapted to engage a log positioned on said support member; and
(b) wedge means extending above said support member at one end thereof for engaging and splitting the log forced against said wedge means by said ram means.
4. The apparatus of claim 3 wherein said wedge means includes a knife edge having a leading portion for initially engaging the log positioned on said support member.
5. The apparatus of claim 3 wherein said ram means comprises a push rod connected to said slide means and movable along with said slide means responsive to said linear reciprocal movement imparting means.
6. A tractor supported and driven apparatus for removing tree stumps and splitting logs, comprising:
(a) a frame structure adapted for generally horizontally positioning relative to the ground surface and forming spaced elongated guide members;
(b) three point hitch means for connection of same frame structure to lifting apparatus of a tractor;
(c) a slide structure being movably positioned in sliding engagement with said elongated guide members;
(d) a hydraulic cylinder being supported by said frame structure and having linear driving connection with said slide structure;
(e) a rotary cutter disc being rotatably supported by said slide structure and adapted to cut away a stump from one side thereof as said cutter disc is rotated and moved linearly responsive to linear movement of said slide structure, said cutter disc extending to a level below said frame being capable of removing said stump to a grade below ground level, said cutter disc being independently rotated by the power-take-off of said tractor and independently moved in linear manner upon linear movement of said slide structure by said hydraulic cylinder; and
(f) log splitting means mounted on said frame structure for splitting a log positioned thereon.
7. The apparatus of claim 6, wherein:
(a) said frame structure is of generally horizontal form having a forward portion and a rear portion, said rotary cutter disc being positioned for linear movement between said forward portion and said rear portion;
(b) a three point hitch connection is provided at said forward portion of said frame structure forming spaced lower hitch elements and a central elevated hitch element;
(c) force transmitting structural means are connected to said central elevated hitch element and extend over said cutter element, said force transmitting structural means being connected to said rear frame portion; and
(d) said rear frame portion supporting a horizontally disposed guide member for receiving a log thereon.
8. The apparatus of claim 7, including:
(a) ram means being positioned for guided reciprocal movement relative to said guide member and adapted to engage a log positioned on said guide member; and
(b) wedge means extending above said guide member at one end thereof for engaging and splitting a log forced against said wedge means by said ram means.
9. The apparatus of claim 8 wherein said wedge means comprises an upstanding portion of a frame member extending above said horizontally disposed guide member, said wedge means including a knife edge having a leading portion for initially engaging the log supported on said guide member.
10. The apparatus of claim 9 wherein said ram means comprises a push rod connected to said slide means and movable along with said slide means responsive to linear reciprocal movement of said hydraulic cylinder.
Description
RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. Ser. No. 581,917 filed Feb. 21, 1984, now U.S. Pat. No. 4,530,385.

FIELD OF THE INVENTION

This invention relates generally to devices for removing tree stumps and, more particularly, is directed to a tree stump removal apparatus incorporating a log splitter which is supported by the standard three point hitch of a tractor and is driven by the power take-off and hydraulic supply systems of the tractor.

BACKGROUND OF THE INVENTION

After trees have been cut, such as during tree harvesting operations or land clearing operations, there typically remains a section of tree stem extending above the surface of the ground. This section of the tree stem, typically referred to as a tree stump, results due to cutting of the tree at a level above the ground where the trunk or stem of the tree begins to taper outwardly to the root portion thereof. In many cases tree stumps are left for natural environmental decomposition (such as weather, insects and the like). Tree stumps are also removed by explosives, although this is a dangerous and expensive practice.

Should it become desirable to use the ground surface before the tree stumps have time for natural decomposition, the tree stumps can present a hazard to the intended user. It may, therefore, become desirable to accomplish efficient removal of the tree stumps to a level at or slightly below the grade level of the ground without causing undue disturbance of the ground such as would occur during stump removal by such mechanical implements as dozers, or by blasting, etc.

After the trees have been cut during tree harvesting or land cleaning operations, the trees are typically further cut into logs suitable for sale as firewood. The logs are typically split and bundled to be sold as firewood or the like. To this end, the apparatus of the present disclosure includes a splitter or knife for splitting logs utilizing the hydraulic supply systems of the tractor while removing tree stumps.

THE PRIOR ART

As is clear from a review of the prior art, many different types of stump removers have been developed. For the most part, these devices are of complicated and expensive construction. The stump removal machine of Bartlett, U.S. Pat. No. 2,887,134, and Pickel, U.S. Pat. No. 3,732,905, are supported by the three point hitch structure of a tractor and driven by the power take-off system of the tractor. U.S. Pat. No. 2,9121,022 of Ver Ploeg et al shows a tractor drawn wheel mounted stump cutter device. U.S. Pat. No. 2,927,613 of Franzen et al shows a tractor supported stump cutter having plural saw blades for cutting of the stump. U.S. Pat. No. 3,028,691 of Jeffres discloses a tractor-supported device having a chain type cutter driven in rotary manner. Other stump cutting devices of interest are disclosed by U.S. Pat. Nos. 3,044,509 of Kehler, 3,308,860 of Deshano, 3,568,740 of Speakman, 3,911,979 of Rousseau and 4,271,879 of Shivers, Jr. et al.

SUMMARY OF THE INVENTION

Accordingly, it is a primary feature of the present invention to provide novel stump removal apparatus which may be supported, raised, lowered and driven by a conventional tractor having a three point hitch.

It is also a feature of this invention to provide novel tree stump removal apparatus which is capable of efficiently reducing tree stumps to small size debris such as saw dust and wood chips which need not necessarily be transported from the stump removal site.

It is an even further feature of this invention to provide novel tree stump removal apparatus which may be simply and efficiently controlled for removal of tree stumps to the grade level of the ground or to grade levels either below or above ground level as desired by the user.

It is an important feature of this invention to provide novel tree stump removal apparatus which is supported by the three point hitch of a standard tractor and is driven by the power take-off and hydraulic systems of the tractor, thus minimizing the mechanical requirements and expense of the mechanism.

It is also an important feature of this invention to provide novel tree stump removal apparatus incorporating a log splitter.

It is an even further feature of this invention to provide novel tree stump removal apparatus which may be simply and efficiently stored in readiness for use.

Briefly, tree stump removal apparatus constructed in accordance with the present invention incorporate a frame structure adapted for generally horizontal positioning relative to the ground surface and forming a pair of generally parallel elongated guide members which comprise a portion of the frame structure. A slide structure is provided with guide channels at opposite sides thereof for guiding engagement with the elongated guide members of the frame. A hydraulic cylinder is fixed to the frame structure with an operating shaft thereof in driving connection with the slide and thus being adapted to impart linear movement to the slide upon being energized through control of the hydraulic system of the tractor. A rotary cutter disk having tree trunk milling or cutting teeth removably fixed thereon is rotatably supported on the frame structure and is therefore movable along with the frame. The cutter is adapted to mill or shred away a tree stump from one side thereof as the cutter disk is simultaneously rotated and moved linearly by hydraulically induced movement of the slide structure. The cutter disk is capable of removing the stump to the level of the ground or to grade levels either above or below the level of the ground depending upon the desires of the user.

The frame structure incorporates a plurality of jack stands which are extended downwardly to elevate the frame from the ground for storage or positioned upwardly while the apparatus is being supported by a tractor. This feature permits lowering of the frame structure to ground level for removal of stumps below ground level since the outer periphery of the cutter disk extends below the lower level of the frame structure. The frame also incorporates vertical lifting eye structure enabling it to be lifted by lifting hooks such as for handling or transportation without attachment to a tractor.

The rotary cutter disk is in the form of a metal plate having a plurality of wood cutting or shredding teeth extending from one side and the peripheral portion thereof. The cutter disk is rotated by the power take-off system of the tractor while, at the same time, it is moved linearly against the side portion of the tree stump. The cutter disk is rotatably supported by a bearing secured to the slide structure. A non-circular drive opening is defined by the cutter which receives an elongated non-circular drive shaft extending across a tree stump opening formed by the frame member. The elongated drive shaft is rotated by the power take-off system of the tractor and maintains its driving relation with the rotary cutter during linear movement of the slide by the hydraulic cylinder. A very simple, low cost disk drive system is therefore provided which minimizes the total cost of the stump removal apparatus. The disk is enclosed by a protective housing having a suitable outlet for discharge of particles removed from the stump. Suitable collection apparatus may be provided at the housing discharge in the event the stump particles are to be collected for disposal away from the stump removal site.

The rear extension of the frame structure supports a guide member for receiving a log thereon. The log support member is supported above and parallel to the rear extension at one end by an upstanding frame members and at the other end by a transverse brace member. A plunger having one end secured to the slide structure extends through the brace member and is supported thereby. The plunger reciprocates during linear movement of the slide structure. The reciprocating action of the plunger forces logs placed on the log support member against a knife edge formed on the upstanding frame member, thereby splitting the logs utilizing the hydraulic system of the tractor.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner of the above recited features advantages and objects of the present invention will become apparent and can be understood in detail, more particular description of the invention briefly summarized above, may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification.

It is to be noted, however, that the appended drawings illustrate only a typical embodiment of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is an isometric view illustrating tractor supported and operated stump removal apparatus constructed in accordance with the present invention and with the cutter disc thereof shown in the broken line.

FIG. 2 is a top plan view of the tree stump removal apparatus, partially broken away, showing a log portion to be split; and

FIG. 3 is a sectional view of the tree stump removal and log splitting apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now simultaneously to FIGS. 1-3 of the drawings, a mechanism for removing tree stumps is provided generally at 10 which incorporates a tractor supported frame structure illustrated generally at 12. A major portion of the frame structure is of generally rectangular form and is defined by a pair of elongated structural frame members 14 and 16 which are disposed in substantially parallel relation and which are interconnected by means of a pair of transverse structural members 18 and 20. The frame members 14, 16, 18 and 20 cooperate to define an opening 22. The parallel structural members 14 and 16 define support extensions 26 to which is connected a three point hitch assembly illustrated generally at 30. The hitch assembly includes a pair of inclined load transmitting members 32 and 34 having bifurcated lower portions 36 and 38 defining clevis-like connections. A pair of connecting pins 40 and 42 extend through side members of the clevis structure for connection of hitch operating bars 44 and 46 of a tractor to the three point hitch structure. The hitch operating bars form a part of the tractor hitch structure as does the operating bar member 48. A connecting pin 50 extends through apertures in the upper parallel extremities of the load transmitting members 32 and 34 thus providing for connection of the free extremity of the lift bar 48 of the tractor to the upper portion of the three point hitch assembly. A force transmitting member 54 is provided to transmit forces from the three point hitch to the frame structure of the stump removal apparatus. Inclined structural members 57, 58, 59 and 60 are secured at the upper extremities thereof to the central force transmitting member 54 and are positioned in downwardly diverging manner with the lower extremities thereof secured to the transverse structural frame member 18. Additional structural support is provided by structural members 61 and 63 secured at approximately the midpoint of inclined structural members 58 and 60, respectively, extending angularly toward a rear extension of the frame structure and secured thereto by welding or the likes.

The rear extension of the frame structure is shown generally at 62. The rear extension 62 is formed by elongated parallel structural members 64 and 66 which are connected by welding or the like to the transverse structural member 18. A rear transverse structural member 68 interconnects with parallel structural member 64 and 66 and cooperates therewith to define a generally rectangular opening within which is located a hydraulic cylinder 72. The rear end 74 of the cylinder is connected to a connection tab or flange 78 extending forwardly from the structural member 68. At the forward portion of the hydraulic cylinder 72 the operating shaft 80 thereof extends through openings in the transverse structural member 18 thus positioning an operating clevis 82 at the free end of the operating shaft 80 within the rectangular opening 22 of the frame structure. The clevis 82 is connected by a pin 84 to a connecting tab member 88 extending from an elongated structural member 90 which forms a portion of a slide member shown generally at 92. Thus, as the hydraulic cylinder 72 is energized responsive to selection by the tractor operator, the operating shaft 80 of the cylinder imparts linear movement to the slide structure 92. The slide structure incorporates a pair of guide members 94 and 96 which are formed by elongated channel members having a C-shaped cross-sectional configuration with upper and lower flanges receiving the elongated structural members 14 and 16 in guiding relation therebetween. The slide structure may also includes a spaced transverse structural member 98 at the opposite side thereof which is also interconnected with the guide channels 94 and 96.

A pair of bearing assemblies 100 are fixed in aligned relation to the transverse structural members 18 and 20 of the framework in the manner shown in FIGS. 1 and 3. These bearings provide rotatable support for a non-circular drive shaft 104 which is rotated by a power take-off shaft 106 extending from the power take-off of the tractor. The drive shafts 104 and 106 are interconnected by means of a universal joint in order to accommodate any shaft misalignment that might be present.

The slide assembly 92 forms an opening 110 within which is located a circular cutter plate or disk 112. The cutter disk 112 is rotatably supported by means of a bearing assembly 114 secured to the transverse structural member 90 of the slide assembly. Thus, the bearing assembly 114 and the disk 112 move linearly as the slide assembly 92 is moved upon energization of the hydraulic cylinder 72. The bearing support assembly for the cutter disk defines a non-circular drive opening which receives the non-circular drive shaft 104 in linearly movably, non-rotatable driving relation therein. As the drive shaft 104 is rotated, the cutter disk 112 is caused to rotate. As the slide assembly 92 is moved linearly by the hydraulic cylinder 72 the drive shaft 104 does not move linearly but rather merely continues its rotary movement responsive to its directly driven relationship with the drive shaft 106 of the tractor power take-off shaft. The rotary cutter disk, however, is advanced for cutting of a tree stump as the slide assembly 92 is advanced by the hydraulic cylinder 72. It shall be borne in mind that the hydraulic cylinder incorporates hydraulic supply lines at 118 and 120 (not shown in the drawings) which extend to the hydraulic supply system of the tractor. By appropriate manipulation of an actuating valve, the hydraulic cylinder and, consequently, the slide assembly 92 will be actuated in a selected forward or rearward direction.

A protective housing 134 is secured to the guide members 94 and 96 of the slide assembly and may also be secured to one or both of the transverse structural members 90 or 98 as desired. The side plates of the housing structure form openings such as shown at 136 through which the non-circular drive shaft 104 extends. The housing structure therefore travels along with the movable slide assembly and thus provides a protective enclosure about the rotating cutter disk 112. The housing is removably connected to the slide assembly 92 by hinge type receptacles which are retained in assembly by hinge pins. The housing can be pivoted relative to the slide assembly 92 by removing one of the hinge pins, or removed from the slide assembly 92 after both of the hinge pins have been removed.

The rear extension 62 supports a log splitting assembly comprising a log support member 116 which is supported above and parallel to the rear extension 62. The support member 116 is welded at one end to a transverse brace 118 extending between the inclined structural member 57 and 59. The transverse brace 118 is welded to the structural member 57 and 59 at each end thereof. The rear end of the support member 116 is welded to an upright frame member 120, which frame member 120 is welded at its lower end to the frame member 68. The support member 116 is horizontally disposed between the base 118 and the frame member 120 presenting a substantially flat surface for receiving a log 121 thereon as best shown in FIGS. 2 and 3.

The frame member 120 includes a wedge portion 119 projecting above the surface of the support member 116. The wedge 119 is defined by inwardly sloping sides forming a cutting edge 122 for engaging and splitting a log placed on the support member 116. The cutting edge 122 is sloped slightly toward the log 121 as shown in FIG. 3. In this manner, the log 121 is first engaged by the upper tip of the cutting edge 122 so as to facilitate splitting of the log. In addition, the slopped profile of the cutting edge 122 tends to hold the log 121 by providing a downward force as the log is forced past the wedge 119.

As shown in FIGS. 2 and 3, the back end of the log 121 is engaged by a ram plate 123 connected to a push rod 124. The push rod 124 extends through an aperture in the brace 118 and is welded at its opposite end to an inverted, substantially V-shaped frame member 125. The legs of the frame member 125 are welded to the slide frame member 90. Thus, actuation of the hydraulic cylinder 72 to move the slide assembly 92 also reciprocates the push rod 124. Thereby, applying a force to the back end of the log 121 and forcing the log past the wedge 119. The log 121 is thus split in half. The process may be repeated for each half of the log 121 is quarter sections are desired.

While the apparatus shown in the drawing is disconnected from a tractor assembly, it is capable of being stored in an elevated position above ground level to thus provide it with a degree of protection from the ground environment and to prevent the cutter disk 112 from engaging the ground. A plurality of jack receptacles 138, 140 and 142 are secured to respective structural members of the frame. Each of these receptacles receives a jack stand such as shown at 142, 144 and 146 which is capable of selective positioning in either an extended position as shown in FIG. 1 or a retracted position. Each of the jack stands defines one or more pin apertures 148 which receive pins to lock the jack stands in either the extended or retracted position as desired. In the extended position as shown in FIG. 1 the jack stands rest on the ground and therefore support the frame structure 12 in an elevated position. During use, the jack stands may be retracted, thus enabling the frame to be lowered into contact with the ground for positioning a cutter disc such that it enters the ground to its fullest depth to thereby facilitate removal of a stump below ground level. The degree of disc penetration below the level of the ground can be effectively controlled through positioning of the jack stands.

To further facilitate handling, the upper transverse structural member 54 is provided with lifting eyes 150 and 152 which permit movement of the stump removal mechanism by any suitable lifting apparatus such as for truck loading for relocation of it when a tractor is not available or when the apparatus is to be transported significant distances.

OPERATION

For stump removal operations, the connecting bars 44, 46 and 48 of a convenient tractor power take-off are interconnected with the three point hitch structure by means of the connecting pins 40, 42 and 50. The jack stands are then shifted to the retracted positions thereof, such as shown in FIGS. 2 and 4 thereby permitting the frame 12 to be lowered into contact with the ground if desired. The tractor will then transport the mechanism in elevated position above the ground and will sufficiently raise it to clear a stump intended for removal. The tractor will then be backed up to position the opening 22 of the frame structure over the stump. Thereafter, the tractor lift will be lowered, thus lowering the frame to a suitable height relative to the stump. In this position, the hydraulic cylinder 72 will be so energized as to position the slide assembly 92 at its left-most, retracted position. The power take-off of the tractor will then be energized, thereby rotating the drive shaft 106 and thus causing rotation of the driven shaft 104. The driving interconnection between the non-circular shaft 104 and the non-circular opening 116 of the cutter causes the cutter plate to rotate while being supported by its bearing assembly 114.

At this time the hydraulic cylinder 72 will be energized causing the drive shaft 80 to move forwardly toward the tractor and thereby driving the slide assembly 92 and the rotary cutter disk 112 toward the stump. As the cutter disk 112 advances, the cutter teeth engage the stump and begin cutting it away. The sawdust and wood chips that are removed from the stump will be ejected through an opening 154 of the protective housing 134 to thus insure that the operator of the tractor is not in danger by flying wood chips and other debris. If desired, a suitable receptacle may be connected at the housing opening 54 to receive the sawdust and woodchips that are thus developed. The hydraulic cylinder and its shaft are of sufficient length that a stump will be completely cut away in a single pass. In the event the stump is of greater height than the cutting depth of the cutter disk after an initial pass, cutting away the upper portion of the stump, the slide assembly 92 will again be retracted by the hydraulic cylinder. Thereafter the frame will be lowered and the hydraulic cylinder energized to move the slide assembly and the cutter across the stump again, thus removing the stump to a lower level, including below ground level, if desired. If desired, the rotating stump cutter disk may be inserted into the ground while rotating by simultaneously lowering the frame toward the surface of the ground. In fact, the frame may be lowered into contact with the ground if desired and the hydraulic cylinder may be energized to cause cutter traversing below ground level. Obviously the rotating cutter will dig a trench below ground which, of course, must be filled after the stump has been removed if a trench in the ground is undesirable.

Upon retraction of the hydraulic cylinder 72, the push rod 124 is moved toward the wedge 119. A log 121 placed on the support member 116 would thus be forced against the wedge 119 by the rod 124 and split by the knife edge 122.

It is therefore seen that this invention is one well adapted to attain all of the objects and advantages hereinabove set forth together with other advantages which will become obvious and inherent from a description of the apparatus itself. It will be understood that certain combinations and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the present invention.

As many possible embodiments may be made of this invention without departing from the spirit or scope thereof, it is to be understood that all matters hereinabove set forth or shown in the accompanying drawings are to be interpreted as illustrative and not in any limiting sense.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2887134 *Aug 28, 1958May 19, 1959Jack BartlettStump removing machine
US3911979 *May 13, 1974Oct 14, 1975Rousseau JosephDevice for cutting down tree stems
US4530385 *Feb 21, 1984Jul 23, 1985York Norman NApparatus for removing tree stumps
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4998573 *Nov 17, 1989Mar 12, 1991York Norman NTree cutting apparatus
US5034407 *Apr 23, 1991Jul 23, 1991Hooser Steven MPortable stump remover
US5269355 *Sep 8, 1992Dec 14, 1993Bowen Randal GCutting wheel for stump-grinding apparatus
US5375638 *Oct 13, 1993Dec 27, 1994Clarke Power Products, Inc.Log splitter
US5381840 *Aug 20, 1993Jan 17, 1995Bowen; Randal G.Stump-grinding apparatus
US5435359 *Jun 30, 1994Jul 25, 1995Craft; Robert J.Stump grinder with transversely mounted cutter wheel
US5655581 *Jun 6, 1996Aug 12, 1997Craft; Robert JefferyTractor-mounted stump grinder with laterally and longitudinally movable cutter wheel
US5829497 *May 30, 1997Nov 3, 1998Maroney; Freeman D.Telescoping and reciprocating stump grinder
US6263930Apr 11, 2000Jul 24, 2001Scott A. WileyStump grinder
US7150300Sep 23, 2003Dec 19, 2006Bay Engineering, Inc.Disc-type stump grinder
WO1991010354A1 *Jan 16, 1991Jul 17, 1991Steven M HooserPortable stump remover
Classifications
U.S. Classification144/4.6, 144/24.12, 144/193.1
International ClassificationA01G23/06
Cooperative ClassificationA01G23/067
European ClassificationA01G23/06C
Legal Events
DateCodeEventDescription
Jan 24, 1995FPExpired due to failure to pay maintenance fee
Effective date: 19941116
Nov 13, 1994LAPSLapse for failure to pay maintenance fees
Jun 21, 1994REMIMaintenance fee reminder mailed
May 2, 1990FPAYFee payment
Year of fee payment: 4